And the last season of Babylon5 was actually somewhat bad because of that episode they already shot, because they had to replace a lot of actors its a bit hap-snap in the last season (currently re-watching it on DVD) because they already finished a lot at the end of season 4.
The last season sure was bad, but that wasn't the pre-shot final episode's fault. All the main plotlines were ended in season 4, and they really didn't have enough stuff to continue on season 5. But think if they had cancelled the series in the middle of the fifth season? How crappy solution would that have been.
The unrated and extended DVD runs 103 minutes, about16 minutes longer than the Sci-Fi Channel broadcast.